The present invention relates to a novel process for the preparation of aminodiarylazo compounds by reducing nitrodiarylazo compounds using 1,2-alkanediols or 1,2-aminoalkanols. The novel process is particularly environmentally compatible and gives the desired compounds in good yields.
It is known that nitrodiarylazo compounds can be converted into the corresponding trisazo- or disazoazoxy compounds by treating them with sugars, such as glucose. Cf. German Patent Application DE-A 694,965. Surprisingly, it has now been found that substituted nitrodiarylazo compounds can react in a certain way with 1,2-alkanediols or 1,2-aminoalkanols to give the corresponding aminodiarylazo compounds.